Ruth Dorel, PhD student under the supervision of Prof. Antonio M. Echavarren (ICIQ), has defended her PhD Thesis entitled
“New Annulation Strategies: From Polycyclic Aromatic Hydrocarbons to Natural Products”‘ (assigned to the Organic and Analytical Chemistry Department of the Universitat Rovira i Virgili) publicly on February 10th at the ICIQ Auditorium.
The members of the evaluation committee were: Prof. Sergio Castillón (Universitat Rovira i Virgili), Prof. Olga García Mancheño (Universität Regensburg) and Prof. Nazario Martín (Universidad Complutense de Madrid)
Dr. Dorel with her supervisor, Prof. Echavarren and the evaluation committee.
Abstract
This PhD thesis covers three fields of synthetic organic chemistry devoted to the synthesis of new materials based on polycyclic aromatic hydrocarbons (PAHs), the development of new metal-catalyzed synthetic methodology, and the synthesis of natural product derivatives.
The development of new strategies for the precise synthesis of structurally well-defined novel graphene cutouts is a field of great interest due to their potential implementation in molecular electronic devices. In this context, an efficient synthesis of a new disc-shaped highly symmetric C54H20 graphene fragment – tetrabenzocircumpyrene – was developed, and its electronic properties were examined by scanning tunneling microscopy (STM).
Acenes represent another appealing class of PAHs due to their semiconducting properties. Nonetheless, their applicability in electronic devices is limited by their poor solubility and their inherent instability. One approach to circumvent these limitations is the preparation of more stable partially saturated derivatives, which can be used as precursors of the conjugated systems. Thus, a selective method for the preparation of partially saturated acenes was developed based on a gold(I)-catalyzed cyclization of suitable 1,7-enynes, which allowed the preparation of functionalized hydroacenes with up to nine linearly fused rings.
The outstanding ability of gold(I) complexes to construct complex polycyclic frameworks was also examined in the context of the synthesis of natural products. Thus, the gold(I)-catalyzed alkoxycyclization of cyclopropyl-tethered 1,6-enynes allowed the ready assembly of the [3,5,5,7] tetracyclic skeleton of the echinopines, which opened an entry for the preparation of functionalized derivatives of these natural products.